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Welcome to the Cisco Networking Professionals Ask the Expert conversation.  Service Provider and Enterprise network engineers are facing one of the major challenges since the inception  of the Internet; the transition to IPv6. Several tools and techniques are available today to ease this major undertaking. This ask the expert session with Harold Ritter focuses on some of the tunneling  techniques such as static tunnels, 6to4, isatap, 6rd and some of the translation mechanisms such as nat444, nat64, dual stack lite that will help network engineers reach their objective  of making IPv6 ubiquitous.  Harold Ritter is a technical leader with the Cisco Advanced Services Central Engineering team. He is responsible for helping Cisco top-tier Service Provider  customers to design, implement and troubleshoot routing protocols and multicast, for both IPv4 and IPv6, and MPLS solutions in their environment. He is a regular contributor to CiscoLive.  He has been a network engineer for more than 14 years. Harold is a CCIE (#4168) for Routing & Switching and Service Provider.

Remember to use the rating system to let Harold know if you have received an adequate response.

Harold might not be able to answer each question due to the volume expected during this event. Our moderators will post many of the unanswered  questions in other discussion forums shortly after the event. This event lasts through November 5, 2010. Visit this forum often to view responses  to your questions and the questions of other community members.

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‎10-22-2010 02:57 PM
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New Member

Hi Harold

Pls could you explain the IOS (software) feature
"IPv6 data link: VLANs using IEEE 802.1Q encapsulation",
which is formally not a part of the Catalyst IOS IP BASE set.

Our Design:

a) ASA <== 802.Q ==> Catalyst Layer-2-only <== 802.Q  ==> ISR 15.M/T

b) ASA <== 802.Q ==> Catalyst Layer-2-only <== access ==> any servers

No problems exist with the case b) - ND is working very well in both directions.

In a) the ND (ipv6 neighborhoods) are not completed for global unicast addresses.
LL-addresses are reachable (e.g. by ping). the ASA is the default gateway for
ISR subinterfaces. So we are able to ping the unicast address ASA from ISR; just
thereafter, the ASA has the ISR addresses and transit traffic to the outside...

I assume we run into an issue with the "feature". We'd like to
stay with IP Base; nevertheless we have tested IP Services too

For "802.Q-Multi-Hop" the current workaround is entering of static neighbors
on ASA 8.3(2)-x.


MLD snooping is Disabled on Catalyst

Cisco Employee

Hi Arto,

This should not be an issue in either one of the above scenarios. I also suspect that you are hitting and issue with the specific level of code you are using. May I suggest that you work with TAC to narrow down on the specific issue you are hitting.


New Member

Is there many SP deploying IPv6 currently?

Thanks Steve

Cisco Employee

Hi Steve,

There is definitely a lot of activities currently in the SP field surronding IPv6. All SP customers I work with or come across these days have either already deployed IPv6 or have concrete plans to do so in the very near future. The ways in which they deploy are very different from one SP customer to another. Some have decided to bite the bullit and to deploy IPv6 in dual stack mode throughtout their core infrastructures. Some use thei existing MPLS core to simply tunnel IPv6 through their core. Some go with a mix and match of dual stack and tunneling techniques. Let me know if you need more information.


New Member

Hello Harold,

I have an AP 1131 AG and it is in H-Reap mode; for right now both radio 802.11a and 802.11b/g are disable, when I try to make it enable it give me error in WCS "Error Common-1: Some unexpected internal error has occurred. If the problem persist report to the Tech Support. And the second error

" Error : SNMP operation to Device Failed; Attempted to set conflicting attribute value.

I will appreciate your help.

Kindest Regards,

Sal Afridi

Cisco Employee is a community driven resource tracking IPv6 enabled ISPs.